You need to end up with 3 separate pairs of SRM servers, 1 each for the 3 arrays. Then you install the SRA on each and create array-pairs separately on each one.
See the documentation: Installing Site Recovery Manager to Use with a Shared Recovery Site
And this blog post for details about SRM and multiple sites/pairs: SRM Multi-Site Options - Virtual Blocks
Keep in mind that the separate SRM instances will not be aware of each other so make sure that there isn't any overlap in what they manage.
It may be that the SRA (which comes from DellEMC) doesn't support having multiple pairs with the same source/target array? I suggest reaching out to DellEMC as well if you can't get this to work. As an alternative you could look at using vSphere Replication which doesn't require SRAs.