How to Freeze Budget?

Summary:

Hello Experts,

We currently have two plans - Budget plan and Increment plan.
In Budget Plan, we are deciding only budget using Worker Level Budgeting and cross referencing the budget from Budget Plan in Increment Plan main allocation worksheet.

Here, in both the plans we have some common parameters so if we are changing any field in Increment Plan the budget in the Budget Plan is also impacted.

Please let me know how we can freeze the Budget using first plan and can use that fixed budget in next plan even if there will be any change in Increment Plan.