Sorry for my delayed response. So, this is how I have it structured on my app.
Now, all I want is to create a piechart on the project level to show accurately as to how much % each project is done, based on task status on all tasks assigned to a project. But I also wanted to filter and see the piechart at project phases level as well within a project.
I was originally thinking that I need to capture an average % of status on Tables 2 and 3 and then calculate the project % based on the average pulled in table 2 and 3. I might be wrong with my approach.
You can summarize the number of Tasks in each status on the Projects table (from the relationship settings) then use a formula to display the % complete on reports & forms.
You can create the pie chart on the Tasks table, then have is displayed on the Projects record. ie your users will have to click into the project to see the pie chart status breakdown. < This is the suggestion I made in my prior post.
From your post it sounds like you want the visual of the Pie Chart. When you a report/chart from a child table onto the parent record it will automatically filter it to only show the related records (even if it normally shows all records on the child table).