The Single Member LLC is "disregarded" (assuming it did not make an election to be taxed as a corporation). In other words, you ignore that it exists and treat the income and expenses as if the owner incurred them.
So that means you treat it as if the Multi-Member LLC incurred the income and expenses. Unless your State has other requirements for LLCs (for example, California or Texas), nothing needs to be done with the Single Member LLC other than putting the income and expenses on the Partnership return.
