The display type of an item line field needs to be set as disabled for some users. The workflow can be used for this purpose.
In the workflow, even though the ‘Set Field Display Type’ action is not available for sublist action groups, it can be achieved without the sublist action group.
Select the ‘Set Field Display Type’ action. In the parameters section, select the Sublist option. Then the ‘Field’ dropdown will show the item line fields. Otherwise, it will not show the line-level fields.
Set the appropriate condition and trigger points.