Perhaps they have no CoI at the moment? In which case you should do nothing 
If they do have CoI related to OSM, as Working Group Conflict of Interest Policy - OpenStreetMap Foundation (which also applies to moderators) says, they should declare it:
- Working Group Members should list employers, directorships, and other similar affiliations on the WG membership page if their organisation does business related to OpenStreetMap.
(there is no “WG membership page” for community forum moderators though, so the community forum user page or wiki is probably the best place to do it. It’s not a big deal, but the document could use some brushing-up to more cleanly cover all categories it applies to).
If in doubt, I would ask in thread in that category each moderator explicitly to list/update their potential CoI affiliations (in case they forgot to update their user page), or to state explicitly if they have no potential CoI related to OSM.
But I see you seem to have done it already for Brasil category, and got an answer in Brasil - Revalidação dos moderadores - fevereiro de 2024 - #25 by matheusgomesms with list of current moderator affiliations.
If you doubt the truthfulness of those information, I would suggest you provide other information which you may find might be in conflict with stated affiliations and ask for clarifications on seemingly conflicting information in polite way (instead of, for example, engaging in potential libel, attacks, accusations or other sorts on uncivil or non-friendly behaviour)