Hi Preet,

It seems to me that what you are looking for is a network meta analysis.

Since you have multi-arm trials, you probably have multiple treatments and network meta analysis is an extension of meta-analysis to a network of treatments. You can easily find many references for network meta analysis and I just give a review here

Article Twenty years of network meta-analysis: Continuing controvers...

It could be that your groups is the same treatment in different dosages or that you would like to combine groups. In this case, have a look at the Cochrane guidance

https://handbook-5-1.cochrane.org/chapter_16/16_5_4_how_to_include_multiple_groups_from_one_study.htm