In cases like this when posting in the forum, please add a sample PBIX file so we can better assist you. Sounds like you are going to possibly need the SUMMARIZE function so that you can get the correct total for your measure. You can also you the search feature at the top right of the screen to see if something similar has been asked. In your case, this is a very common question. Here is a video from Sam to point you in the right direction, If you need further assistance, please post a sample file.
Thanks
