Overlap two line charts

Both should join with the same dimension and get plotted. Now if they are different table it should happen automatically. In case one table and two dates.

Refer to this file if there two tables: https://www.dropbox.com/s/bu47m5ek7sr9v8t/sales_analytics_v2.pbix?dl=0

For one table two dates: https://community.powerbi.com/t5/Community-Blog/HR-Analytics-Active-Employee-Hire-and-Termination-trend/ba-p/882970

To get the best of the time intelligence function. Make sure you have a date calendar and it has been marked as the date in model view. Also, join it with the date column of your fact/s. Refer :
https://radacad.com/creating-calendar-table-in-power-bi-using-dax-functions
https://www.archerpoint.com/blog/Posts/creating-date-table-power-bi
https://www.sqlbi.com/articles/creating-a-simple-date-table-in-dax/