As part of the temporary short-term solution of the Course hierarchy project, indentation will be back for 4.0 versions going forward, in an improved way to meet accessibility and usability requirements. 

Based on the research conducted for the Course hierarchy project, the findings show that 3 levels of hierarchy are enough for our users, hence the new indentation will allow a maximum of 1 level of indentation in activities, leaving a course structure as follows:

Section > Primary activity (Non-indented) > Secondary activity (Indented) = 3 levels of hierarchy

To better solve the accessibility and usability issues that old indentation was creating, the activity card style will be different when the activity is indented, so users can easily identify the level of hierarchy from the course overview page.

The functionality to indent activities can be accessed through the 'options' icon at the right side of activity cards, under the 'Move right'/'Move left' option.

Figma prototype

https://www.figma.com/proto/Gb8KsnpmxWVnzpxYTZ623P/Course-hierarchy?page-id=27%3A1118&node-id=112%3A6194&viewport=241%2C287%2C0.1&scaling=scale-down&starting-point-node-id=112%3A6194&show-proto-sidebar=1