Show measure from a certain date in a line chart

[pangea]

Hello community!

I need some help with a line chart (see image below).

The measures are:
- red: debts
- green: credits
- purple: current and simulated bank value

The dimensions are on the bottom line: credits' and debts' due dates (years/months/days).

I need the purple line to start from "today()" and sum all the previous debts and credits (current bank value + previous credits - previous debts = updated bank value). Then it must go on with this sum: updated bank value + future credits - future debts.

Could you suggest a solution?
Thank you!