Before I already have tried to move and resize.
But if you change the position or size of the legend it becomes to vertical alignment.
I need a horizontal alignment like below
Go to the General tab in Properties, and press both "Reset User Sizing" and "Reset User Docking." Then try dragging the legend again.
Thanks, I also knew about those buttons and already tried them.
But It is not working.
I thought and got an idea to show it like two layers.
-First chart is graph with hidden legend.
-Second one shows only legend.
I am sure it is not good for performance but it's the result what I need.
I understand that there is a positioning of legend to center is a limitation here..
I tried other alternative, instead of using two objects and overlap each other you can use text in the chart.
Find my approach, let me know if you like it
You can still do changing the positioning using appropriate degrees. screenshot below for your reference.