How to split a pattern piece into 2 or 3 Sewing Machines Parts and Sales in Los Angeles

OK so hopefully I can explain this well enough that someone will understand and be able to help me. I am making a top with a pattern but don’t have enough of the fabric I want to use. Well I have enough but not in the right places. I don’t want to add a seam to the front because I hate that look so I need to turn my front piece of the top into 2 pieces. I’m thinking of making the seam at the sleeve part (it’s a tank top so not really sleeve but the part that goes over the shoulders) that way the main front of the top is all one piece and I’ll just attach the sleeves. What is the best way to split one pattern piece into 2 and allow for seams??