This is a pretty general question so it is tough to give you specifics. If you look at many of the example projects, they contain a function "advertising_init" or some variant thereof. That function sets up a structure of type "ble_advdata_t" which is then passed to the soft device to set up the advertising packet. You can modify the settings of that structure to make it applicable to your design. The only constraints are those imposed by the bluetooth core specification.
