Overlapping tasks time allotment in percentages


I am making a cahrt for a rsearch project. Tasks will run into another. Example: I start my project in July with a literature review (task 1) and will start after a few weeks (begin September) software prototyping (task 2). There will be an overlap between the time periods (the month of September). So 50 % would go to task 1 ad 50 to task 2. Is there a way to indicate the time alloted to the tasks when they overlap?

Task Properties > Resources > Select resource > Change “Unit” column

“Unit” is the percentage of resource time on this task.