My brother and I invested in a property together. We have equal ownership of the property and split the expenses equally. When we file taxes, do we have to split our deductions/expenses equally or can give more deductions (or less income) to the person in a higher tax bracket?
Each person can only deduct expenses that person paid. If you spent $X on deductible expenses for the property, you can only deduct $X. You can't take a tax deduction for yourself on the basis of money your brother spent (nor vice versa).
As for income, in general you and your brother would be free to come to a business agreement to allocate income from the property in any way you like. If you can convince your brother to give you 75% of the income and take only 25% for himself, great. (You might need to have some justification for this if you are equal owners in the property and share expenses equally; otherwise it could be considered a gift from one party to another.) However, that would be pretty pointless; if your brother is in a higher tax bracket, he still gets to keep at least some of every dollar he earns from the property, whereas if he reallocates that dollar to you, he gets none of it. Also, needless to say, most people wouldn't be eager to set up an arrangement that involves giving away part of their income for no reason (even to a sibling).
If you are in US, then partnerships have to file form 1065 where you report partnership's aggregate income and expenses. And then each partner gets 1065 schedule K1 that you need to report on your personal form 1040. Think of this 1065 schedule k1 as another 1099 form.