Adjustment for unrealized profit or loss

Summary:
Post of the Investment and result of the holding company

Content (please ensure you mask any confidential information):

Hello,
We are analyzing the adjustment of the unrealized result, and for the accounting of the investment and result of the holding company, it is necessary to detail both the selling company and the buying company of the group.
This suggests the need to use a custom dimension to include the selling company:
Entity: holding company
ICP: buying company
Custom: selling company
Is this correct, or is there a better practice?
I don't like to create another dimension with group companies.