...
After clicking the Services tab and clicking the Travel link in the Travel section, the Services | Travel page appears. Click the Hotel Per Diem Editor link. The Hotel , the Hotel Per Diem Management page appears.
...
You can now assign the hotel per diem sets to groups of users as you would do with other service rules for travel. See Service Rules to learn how to associate service rules with groups, and follow the instructions in Enabling Travel Rules to enable travel rules including the hotel per diem sets.