A few examples from my collection;
“Give a time when you’ve had to follow rules”
“Give a time you’ve had to go the extra mile to get a job done”
“Give a time you’ve taken on a job that your manager would normally do”
“Give a time you’ve had to work effectively as a team to get a job done”
“Can you Give an example of a course you’ve attended for longer than 2-weeks”
There are literally loads of possible, but they’ll generally be based around safety, team work and customer service (all key attributes). I’ve had a few DMIs and some are more competency based than others. Just relax, take your time with your answers and be specific with your examples (don’t simply say what you normally do in these situations). Also, don’t be afraid to ask to go back to the odd question if you can’t think of an example (you’re only human after all!). Don’t get too bogged down with this, and remember to research the company and have a couple of questions of your own to throw at them when the time comes, to demonstrate your genuine interest. Good luck!