Lǎobǎn chūchāi le.

老板出差了。

The boss is on his business trip now.
Notes:

老板(Lǎobǎn ): boss

出差(chūchāi): go on business trip

了(le): particle word

Example:

A：老板呢？

      Lǎobǎn ne?

     wher's the boss?

B：老板出差了。

     Lǎobǎn chūchāi le.

     The boss is on his business trip now.