Unfortunately there are sometimes areas which overlap. So even though the space titles may be a little ambiguous, there is still some difficulty in determining which is the right one for a Discussion. Some of this is historical in nature.
For example: Agentry products were part of Syclo which was acquired by SAP a few short years ago. Since it did not fit any other mobile related community, it was assigned to SAP for Mobile (which is normal for many mobile related products or topic areas). Since being acquired, it was later redesigned/redeployed on the SAP Mobile Platform (SMP). So many of the configuration/installation issues that come up are now related to SMP, there are quite a few Discussions which relate to Agentry that now show up in the SMP Developer Center. Which community is the right one? I and other Moderators have had this conversation before. The best we can do is based on a judgement call that Agentry questions unrelated to SMP can remain in SAP for Mobile. Those which are SMP related (particularly configuration, installation, or app deployment related) can go into the SMP Developer Center community. However, it is not a hard fixed rule, rather a guideline. If the Discussion is in one or the other and not really clearly specific to one or the other, then we tend to leave them alone.
Similarly for Fiori and SAPUI5, and Theme Designer (Fiori or UI Technology communities), etc.
MII uses SAPUI5 technology, each of which have their own community. Where should an MII SAPUI5 Discussion be assigned??? The Moderators (I am one in each community) need to make a judgement call. I usually assign depending on whether the question is something SAPUI5 experts could best respond to or whether MII knowledge is more applicable. Knowing both technologies, I can often make a good judgement call, but I may not be correct all the time. Then you put in a link to the other community so both sets of experts can view and respond.
Cheers, Mike (Moderator)
SAP Technology RIG