OIDs I'm using in this example

.1.3.6.1.4.1.5454.1.80.4 =
   .iso.org.dod.internet.private.enterprises.trango.tbw.ptp.gige
 or
   GIGA-PLUS-MIB::gige
.1.3.6.1.4.1.5454.1.80.4.1.1.3.0 =
    .iso.org.dod.internet.private.enterprises.trango.tbw.ptp.gige.eth1.config1.gigeEth1Enable.0
 or
   GIGA-PLUS-MIB::gigeEth1Enable.0

I am attempting to discover a complex OID
My discovery rule specifies .1.3.6.1.4.1.5454.1.80.4

I am attempting to discover (among others) .1.3.6.1.4.1.5454.1.80.4.1.1.3.0
When discovery occurs, {#SNMPINDEX} is set to 'th1Enable.0'

This is not helpful. Either of the following would be correct
1.1.3.0
eth1.config1.gigeEth1Enable.0