Select records from vertical row and transform horizontal row

Just do a simple pivot by aggregating your rows to the desired level (UserName,TaskCode) and then pivoting using MAX or MIN(CASE WHEN .... END)

Like so:

SELECT tm.UserName ,tm.Task_Code ,MIN(CASE WHEN tm.Action = 'START' THEN tm.Badge_IN_OUT_TIME ELSE NULL END) AS Badge_IN_TIME ,MAX(CASE WHEN tm.Action = 'END' THEN tm.Badge_IN_OUT_TIME ELSE NULL END) AS Badge_OUT_TIME FROM task_mgmt AS tm GROUP BY tm.UserName ,tm.Task_Code 

This is a type of gaps-and-islands problem, the islands are pairs of START and END.

There are a number of solutions. Here, I have assumed that START always defines the beginning of each group, and there may or may not be an END.

We can calculate a grouping number for each island by using a windowed COUNT, partitioning by UserName and Task_Code. We then simply group up also by the new grouping number, and pivot the timestamp.

SELECT t.UserName, t.Task_Code MIN(CASE WHEN t.Action = 'START' THEN t.Badge_IN_OUT_TIME END) Badge_IN_TIME, MAX(CASE WHEN t.Action = 'END' THEN t.Badge_IN_OUT_TIME END) Badge_OUT_TIME FROM ( SELECT *, COUNT(CASE WHEN t.Action = 'START' THEN 1 END) OVER (PARTITION BY t.UserName, t.Task_Code ORDER BY t.Badge_IN_OUT_TIME ROWS UNBOUNDED PRECEDING) grp FROM task_mgmt t ) t GROUP BY t.UserName, t.Task_Code t.grp;