Hi @Sbakkalbasioglu ,
The Easify Inventory Sync app can help with your issue 
. You can set up your Sectional product with just 2 options (Fabric & Orientation) and create bundle groups for each Sectional prdocut variant along with the corresponding A, B, and C product variants.
As a result, when a Sectional product is purchased, the quantities of A, B, and C (with corresponding variants) will be automatically updated.
Inversely, if A, B, or C are bought, the inventory of the Sectional product will also be adjusted.
Let me know if you’d like to try the app or need any help with the setup!