Step 1: Locate the scope item that you need to edit the markup on. Then, click the price.
Step 2: Hover over the selection and click on Expand.
Step 3: Click Review and then Proceed. This will not reopen the selection.
Step 4: Scroll to the bottom of the product and edit the markup percentage and click save.
You will then have the option to update just the item in the project or the item in the Design Library as well.
Now you've updated the markup on your selection item!
When the item is a Multicomponent Item
Follow steps 1-3 from above. Then, you will see you can edit the component products in the same way as above.