You can cross-list course sections by merging more than one section together under one parent section. This allows the courses to all come together so you may post one time instead of multiple times. One section will be the parent section retaining all information while the other are child sections up under this parent, which will lose any information within it once cross-listed. It is best practice to merge before course start and especially before any student assignments have been posted. If you must, be sure you download all assignments from the child sections prior to the merge and re-upload into the parent once cross-listed. You open any/all sections to get the 5-digit course ID from the Parent course web address (the one you want to migrate other children's sections into) to easily pull up section when you click Settings>Sections, select the hyperlinked section to open and then select “Cross-List this Section”. It will ask which course to cross-list to and you simply add in parent 5-digit course ID to pull up parent course and then you cross-list course. Repeat process until you have all desired sections under the main/parent section. To check it, go to parent course settings and look under settings. All sections should be listed up under the parent section.
Here is link to the process
Video overviews reflect current feature functionality in Canvas; they are updated based on workflow changes, not on minor or non-functional interface enhancements. Depending on your institution's Canvas theme, the Canvas interface may display differently than shown in this video, but the functionality is the same.