View merge sources
Install the Subversion plugin
This functionality relies on the Subversion plugin, which you need to install and enable.
Press Ctrl+Alt+S to open the IDE settings and then select .
Open the Marketplace tab, find the Subversion plugin, and click Install (restart the IDE if prompted).
For Subversion, the common Viewing Change History functionality is expanded with the possibility to view which revisions have been used in merges applied to a file. Merge sources can be presented as a tree of revisions.
To view the merge source
Open the Version Control tool window, and switch to the Repository tab.
Select the required changelist, and then choose a file from this changelist in the Changed Files pane.
Select Show History from the context menu, or click
on the toolbar. The History tab for the selected file will be displayed. For each revision, the Merge sources field shows the revisions that were used as sources for the merge. 
To view all paths affected by a merge, select the relevant row and press Alt+Shift+A or click
on the toolbar. Review affected paths in the dialog that opens:
