"paths" between two ROLEs

Hi. We emulated a legacy security model (enforced in C/C++ code)
into "layers" of PostgreSQL ROLEs and GRANTs, thus enforced database-side.

To troubleshoot and validate that emulation, I'd like to introspect ROLE
membership to:

1) Output the ROLE "path(s)" between any two ROLEs. Typically between the
LOGIN USER and the ROLE that control access to a particular SCHEMA. In our
model, there can be several ways the two end-roles are connected, involving
a variable number of roles. So it has to be a recursive query.

2) target-end ROLEs (controlling access to SCHEMAs, again) follow a naming
convention, so they can be identified using a LIKE pattern. Output all
target ROLEs (aggregating each "paths" to the source-ROLE in an text[]) a
given LOGIN USER has access to.

I'd appreciate either example SQL for the above; or hints to achieve the
above.
My CTE "foo" is not great, thus reaching out to the community to avoid
wasting too much time on this on my own.

Thanks, --DD