If you utilize the integration between GLM/SLM and CommunitySuite, the Conditional Installment field is available and will sync between CommunitySuite and your GLM/SLM site.
This article explains conditional installments in CommunitySuite: Schedule Grant Payments
This is a system field, and can be added to an installment form in GLM/SLM.
You have the option to fill out the Conditional Installment field in GLM/SLM before syncing the request to CommunitySuite.
Once the request is synced with CommunitySuite, changes to this field can only be made directly in CommunitySuite, and will automatically update the request in GLM/SLM. You also have the option to fill out this field in CommunitySuite prior to syncing a request to GLM/SLM.