can't merge with dffferent branches after upgrading to 3.01

after upgrading to 3.01. I found out that when i tried to merge from url, I couldn't merge any changes like i did with ver 2.XX. any more.

I noticed there is a subtle difference in merge url screen. in version 2.XX, there are two repository dropdowns allow you to select two different branches along with a path or a revision for each one of them. However, in ver 3.01, i found there is only one repository dropdown and two pathes and two revisions selections.

I have tried different combination trying to get it to merge without success.

that make me wonder if i did it right or there is a bug considering the other repository dropdown is missing.

please let me know. thanks.