How to get the destinations of two instances of VLC

i always use busctl to get the complete dbus infos.
There is a system bus (busctl --system) and a session bus (busctl --user) or complete list (busctl -l)
enter:

busctl --user | grep "vlc"

then you get something like this

:1.641 91266 vlc xxxxx :1.641 session-c2.scope c2 - :1.642 91266 vlc xxxxx :1.642 session-c2.scope c2 - :1.643 91266 vlc xxxxx :1.643 session-c2.scope c2 - :1.644 91266 vlc xxxxx :1.644 session-c2.scope c2 - :1.654 91361 vlc xxxxx :1.654 session-c2.scope c2 - :1.655 91361 vlc xxxxx :1.655 session-c2.scope c2 - :1.656 91361 vlc xxxxx :1.656 session-c2.scope c2 - :1.657 91361 vlc xxxxx :1.657 session-c2.scope c2 - org.kde.StatusNotifierItem-91266-2 91266 vlc xxxxx :1.644 session-c2.scope c2 - org.kde.StatusNotifierItem-91361-2 91361 vlc xxxxx :1.657 session-c2.scope c2 - org.mpris.MediaPlayer2.vlc 91266 vlc xxxxx :1.641 session-c2.scope c2 - org.mpris.MediaPlayer2.vlc.instance91361 91361 vlc xxxxx :1.654 session-c2.scope c2 

The org files are the active services.
you see there is a second service called org.mpris.MediaPlayer2.vlc.instance91361
the first vlc instance is on PID 91266, the second vlc instance is on PID 91361

here in my example call:

dbus-send --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.ListQueuedOwners string:org.mpris.MediaPlayer2.vlc.instance91361

will give you your information about the second instance

----------- By the way

you can examine the dbus service for the object tree
busctl --user tree org.mpris.MediaPlayer2.vlc.instance91361

you get:

└─/org └─/org/mpris └─/org/mpris/MediaPlayer2 

then you also can introspect the objects
busctl --user introspect org.mpris.MediaPlayer2.vlc.instance91361 /org/mpris/MediaPlayer2

output:

NAME TYPE SIGNATURE RESULT/VALUE FLAGS org.freedesktop.DBus.Introspectable interface - - - .Introspect method - s - org.freedesktop.DBus.Properties interface - - - .Get method ss v - .GetAll method s a{sv} - .Set method ssv - - .PropertiesChanged signal sa{sv}as - - org.mpris.MediaPlayer2 interface - - - .Quit method - - - .Raise method - - - .CanQuit property b true emits-change .CanRaise property b false emits-change .CanSetFullscreen property b false emits-change .DesktopEntry property s "vlc" emits-change .Fullscreen property b false emits-change writable .HasTrackList property b false emits-change .Identity property s "VLC media player" emits-change .SupportedMimeTypes property as 29 "audio/mpeg" "audio/x-mpeg" "video/m… emits-change .SupportedUriSchemes property as 21 "file" "http" "https" "rtsp" "realrt… emits-change org.mpris.MediaPlayer2.Player interface - - - .Next method - - - .OpenUri method s - - .Pause method - - - .Play method - - - .PlayPause method - - - .Previous method - - - .Seek method x - - .SetPosition method ox - - .Stop method - - - .CanControl property b true emits-change .CanPause property b false emits-change .CanPlay property b false emits-change .CanSeek property b false emits-change .LoopStatus property s "None" emits-change writable .MaximumRate property d 32 emits-change writable .Metadata property a{sv} 0 emits-change .MinimumRate property d 0.032 emits-change writable .PlaybackStatus property s "Stopped" emits-change .Position property i 0 emits-change .Rate property d 1 emits-change writable .Shuffle property d false emits-change writable .Volume property d 0 emits-change writable org.mpris.MediaPlayer2.TrackList interface - - - .AddTrack method sob - - .GetTracksMetadata method ao aa{sv} - .GoTo method o - - .RemoveTrack method o - - .CanEditTracks property b true emits-change .Tracks property ao 0 emits-change .TrackAdded signal a{sv}o - - .TrackListReplaced signal aoo - - .TrackMetadataChanged signal oa{sv} - - .TrackRemoved signal o - - 

you see all defined interfaces and methods.

for example, lets take the "OpenUri" method from the interface: org.mpris.MediaPlayer2.Player

busctl --user call org.mpris.MediaPlayer2.vlc /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player OpenUri s "your url"
-- will open the video in the first instance

busctl --user call org.mpris.MediaPlayer2.vlc.instance91361 /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player OpenUri s "your url"
-- will open a video in the second instance

call Syntax:
============
call SERVICE OBJECT INTERFACE METHOD [SIGNATURE [ARGUMENT...]]
for further information - see busctl - help

have a nice day!