That's not how it works. If you invest $100K in a company and ask them to spend all of that $100K to buy products from another one of your companies, they will laugh at your face.
Just take a look at Snowflake for probably the most successful example (though they still don't make a profit). It seemed like over night ever "big data" tech company I knew started using them aggressively with little other reason than they were the next cool startup whose product you wanted to be using.