My first choice for a two-night hike, with luggage left in a train station locker, would be this:
Start at Kandersteg, a small town in the Berner Oberland between Spiez and Brig. We have left our luggage in lockers there---that was ten years ago but the lockers should still be there ( check to be sure). They had a 48-hour limit at that time, but that should be OK.
Walk through town tomthe gondola and ride the lift up to Oeschinensee. From there, you can hike left or right to reach two SAC huts. I would go left to Blumlialphütte first, overnight there, then loop back to the lake and head up to Freuendenhütte. This is a gorgeous and fun hike on natural ledges, wide and safe, and secured with cables to hold when you want them. The hut sits below the toe of a glacier with incredible views down to the lake below.
These are designated as hikes 9 and 8 on the little map at the bottom of this page.
http://www.oeschinensee.ch/hiking/
The next morning, descend to the lake and ride the gondola back to town to retrieve you luggage.
Other possibilities---although I have no personal experience with luggage storage at these station:
Grindelwald: leave your luggage there and ride the train back to Wilderswil to catch the cogwheel,train up to Schynige Platte. Walk the Panoramaweg along the ridge, with occasional views down tomthe Brienzersee or the other way down to Grindelwald. The hut you are heading to is on the FUlhorn, practically at the summit. The next day you continue on to First ( top station of the gondola down to Grindelwald). You could overnight there or continue around to Grosse Scheidegg. These two are mountain inns rather than alpine huts. From either one it is an easy descent to Grindelwald for your luggage pickup.
Zermatt: there are a number of 2-night walk possibilities from town. Pick from this list of huts, hecking locations on a map:
https://www.zermatt.ch/en/climbing/Mountain-huts
