Investment Type - Validation Logic Merged

Issue? In an Initiative a user selects the *required Pre-defined custom field 'Investment Type' selection of 'Cap' then the user is required to selects a corresponding pre-defined custom field 'UCMGID', likewise if the user in the Initiative selects the 'Investment Type' of 'O&M' then the user is required to select a pre-defined custom field 'billing group'.

Use Case? We require 'Product Strategy & Delivery' Initiatives to capture their funding source in order for Finance to consume an extract from Aha and compare a similar extract from Rally to align the 'Demand' of the delivered 'User Stories (via Features)' for payment via the corresponding 'Funding Id' which is tied back to the Aha Initiative

Expectation? The Aha Tool should have Validation Logic to ensure that the required corresponding data for the Cap and O&M selection is captured in the UCMGID / Billing Group custom fields. Simply said, can we use 'validation logic' to ensure that the required corresponding fields are selected? I.e. Investment Type -> Cap required 'UDMGID' and O&M requires 'Billing Group'.