In the BitBake variables table, in the filters provided for the "Set in file" column, the first one is for "Local configuration variables". That filter should show you any variables set in /build/conf/local.conf and /build/conf/bblayers.conf, but it looks like the existing implementation of the filter only checks for /build/conf/local.conf (see lines 797-797 of views.py). We should add the check for /build/conf/bblayers.conf
On toaster/master:213fef6e87cbf60d773e28d31653e3c626d4058e
commit 7af7e852ea98fbd763108cea07e5ce5d14ffcde3 Test instructions: Filter by the "Local Configuration: files Observe that you see both "local.conf" and "bblayers.conf" files in the table.
verified in master:ac4ff568f5b2ad4f50a1b7b60797e7b797c314bb