"Hold Position" works different in DA:I than it did in DAO. In the latter, the command would remain valid until explicitly revoked by the user, and it would work on the all party members; while in DA:I the command has to be issued to each party member and will be revoked as soon as the player issues another command to that party member (like pressing a button).
That's at least my obersvation so far. 
To make it work, for example to solve a puzzle where you need all four party members at different locations, try the following:
1) Move your main character to location 1 and issue the "Hold Position" command; then switch to your second party member.
2) Move your second party member to location 2 and issue the "Hold Position" command; then switch to your third party member.
3) Move your third party member to location 3 and issue the "Hold Position" command; then switch to your fourth party member.
4) Move your fourth party member to location 4 and issue the "Hold Position" command.
5) Switch to your main character and have them activate the lever, button, or whatever it is they need to do; then issue the "Hold Position" command again.
6) Switch to your second party member and have them activate the lever, button, or whatever it is they need to do; then issue the "Hold Position" command again.
...
7) - 99) Rinse and repeat until all levers, buttons or whatever have been activated
100) Profit!
The trick is that the command is issued to the currently controlled character, and not the rest of the party; and that every action revokes the command. Keep those two things in mind, and you should have no more problems with the "Hold Position" command. 