While using the NetOps Portal to administer Network Flow Analysis, you may notice that you cannot select Custom Virtual Interfaces to an Aggregation.
Component : DX NetOps Network Flow Analysis 20.2.x - 22.2.1
While you were able to select CVI's to be used in the old flash GUI of NFA, the NetOps Portal queries don't allow this.
This will be resolved in Network Flow Analysis 22.2.2. You will be able to select CVI's to be used in Interface Aggregations again.
If you need to build an Aggregation with a CVI and cannot wait for the NetOps 22.2.2 (August 2022) release, then you can utilize the OData API included with NFA:
https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/network-flow-analysis/22-2/reference/network-flow-analysis-odata-api/entity-operations/routers-and-interfaces/interface-aggregations.html#concept.dita_9bffe2bbdfc2cd5f0d09f16b759b518a09505481_AddInterfaceAggregation
You can use the CVI's agent ID like any other agent interface ID to build your Aggregation.