Restrict Currency Selection Based on Currency Type

Hello SAP Community,

We're wondering if it is possible to restrict the currency selection based on the currency type chosen in BEx query filters.

There are two conditions:

1. When user selects Currency Type: 3, the only available MD from the selection will be USD, GBP and EUR.

2. When user selects Currency Type: 2, the only available MD from the selections will be the local currency of the chosen Entity, which is also part of the filters.

Hoping to get an answer as we're stuck in this and cannot find any references regarding Currency restriction via customer exit.

Thank you!