How do I merge 2 or more maps into one wad

[Coconut Crab]

Im planing on making a wad with more than 2 maps but I dont know how to combine 2 or more maps into one wad. If anyone can leave a reply on how to do that.

[ThreeStripes]

 

[strategineer]

 

[thomasthetankengine]

I'm guessing you're using a doom builder. I'm also guessing you're using DOOM 2 as the IWAD, so here's what you have to do.
First, make sure you've already got a map. This will be what I like to call the "Master WAD". Once you're sure you've got a Master WAD, you can then start the process

Start by creating a new map, just like usual. However, instead of typing MAP01 like usual, type MAP02 instead. (see image below if you're confused) Create the map as usual.

Once you've finished building your map, go to file, then select "Save map into.." (See image below if you're confused)
Upon clicking that, that'll open a prompt where you have to go through your files and select the Master WAD, and open that. It'll save, and you'll have your 2 levels in one.

Hope this helped!!