Decide whether the grouping is a set
Kodi's movie sets organise related movies, and a movie belongs to one set. Overlapping themes call for a different model such as tags. Before editing the library, write the purpose of the group: one related collection, a seasonal selection or several overlapping subject views. The purpose determines whether a set is suitable.
Use a small selection of authorised local movies or your own productions. Record the intended set for each item and any themes that overlap. If one movie must belong to several competing set concepts, resolve the model first rather than repeatedly moving it between them. Grouping in a player does not change ownership or permission to share the underlying media.
Work in the library and preserve the previous state
From a library movie's context menu, use Manage > Manage movie set to review membership before changing it. The documented management route is a library operation, not a command that discovers relationships merely from a file-manager view. Keep the old set name and membership list so an unwanted reassignment can be reversed without guessing.
For an original example, a creator may have a three-film workshop series and also a theme called Outdoor Filming. The series can have one coherent set while the topic crosses several works. The example is a catalogue design exercise, not a claim that Kodi has identified a particular commercial franchise or its canonical order.
Set the viewing order without changing visible names
Alphabetical display order may differ from the order you want within a collection. Kodi documents a separate sort title that affects ordering while leaving the displayed title intact. Write the desired sequence in plain language first, then decide whether sort titles are appropriate for that library view.
Record existing sort titles before editing. Choose a consistent convention for the sample and inspect the result in the intended ordering mode. A numbered hidden sort convention should not require renaming the actual media files or replacing accurate visible titles. Keep the order decision separate from set membership, so a correct grouping can survive a later change of viewing preference.
Review small and unusual collections deliberately
Check how the installation displays a set containing only one current member. The Include sets containing a single movie setting affects that presentation, so an absent wrapper does not automatically mean the membership failed. Inspect the stored relationship and the relevant display setting before rebuilding the library.
After the sample is accepted, keep a short policy covering membership, overlapping themes and sorting. Revisit it when adding another release or importing metadata that may supply set information. The result should be an explainable collection view with original files preserved and a record of the deliberate order, not an assertion that one arrangement is correct for every viewer.
Questions answered
Can one movie be in several Kodi movie sets?
The documented model gives a movie one set. Consider tags for overlapping groupings.
Must I rename the displayed movie title to change sorting?
No. Kodi documents a separate sort-title field; preserve accurate display titles and review the ordering mode.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.