What is the ruling on a person sharing money, on the condition that the principal and the discount percentage he obtained from factories are returned as a profit-sharing arrangement (murabahah)?

The described transaction is incorrect and constitutes an interest-based loan, because guaranteeing the capital and the profit for the one who provided the funds invalidates the Mudarabah (definition) (profit-sharing partnership). Its true nature is a loan that brought a benefit to the lender, and every loan that brings a benefit is Riba (usury/interest). It is not considered Murabaha (cost-plus financing) because the one who provided the funds did not genuinely purchase the goods and sell them to his friend. Rather, he gave him money for him (the friend) to purchase for himself. Profit is permissible in trade, not in loans.