how to parse the "CONTAING SEQUENCE" msg immediately about asn1tools HOT 1 OPEN

Hello, as commented in title, when I was trying to decode a msg from 3gpp spec, where there were some formats as below:

UE-EUTRA-Capability-v940-IEs ::= SEQUENCE {
lateNonCriticalExtension OCTET STRING (CONTAINING SEQUENCE {
featureGroupIndRel9Add-r9 BIT STRING (SIZE (32)) OPTIONAL,
fdd-Add-UE-EUTRA-Capabilities-r9 UE-EUTRA-CapabilityAddXDD-Mode-r9 OPTIONAL,
tdd-Add-UE-EUTRA-Capabilities-r9 UE-EUTRA-CapabilityAddXDD-Mode-r9 OPTIONAL,
nonCriticalExtension UE-EUTRA-Capability-v9c0-IEs OPTIONAL
}) OPTIONAL,
nonCriticalExtension UE-EUTRA-Capability-v1020-IEs OPTIONAL
}

Notice that "CONTAINING SEQUENCE" in "lateNonCriticalExtension", however its format was OCTET STRING, so asn1tool would only support to parse it in OCTET string like
"lateNonCriticalExtension":"9C00000005E9000010...”
I'd like to parse the detail information as
"lateNonCriticalExtension":"CONTAINING
{
featureGroupIndRel9Add-r9 '11000000 00000000 00000000 00000000'B,
nonCriticalExtension
{
...”

Thanks a lot!

from asn1tools.