On your disk, copy-paste the .git directory (NB. it might be hidden) from the folder where you have your main-branch on your disk, to the folder where you have your feature-branch on your disk. Then open your feature branch in Mendix studio and do a commit. Thadaah.
Hey Ravi,
I did had similar issue and what did I do is open future branch copy all folder and just pass it to Main branch. Studio pro will show you a lot of differences but nothing to worry about I do it every couple of months when I reach git issue with big repo. Note: I use everything on-premises.
Best regards