Thank you for your question. I understand you are wondering which direction to set the filter in your filter rack.
Most filters will have an arrow stamped on them. This arrow is used to indicate the flow of air to the furnace blower. So you want to install the filter to point towards your furnace blower. Hope that helps answer your question.
If you have any other questions, feel free to post them here and I will do all I can to answer them for you.