That's a file containing text data, so you basically have to export the text files from Mod 1 and import them into Mod 2. You can use Smithbox to do the following:

1. Create a new project with Smithbox, where "Project Directory" is set to the location of Mod 1's files (specifically the folder that contains stuff like regulation.bin, "event", "map", "msg", etc).

2. Go to Text Editor, and on the upper bar, Data > Export Text Entries > Export Modded Entries. Make an empty folder and save the files in there. This should generate a bunch of fmgmerge.json files in it.

3. Create a new project with Smithbox, but this time setting Project Directory to the location of Mod 2's files.

4. Go to Text Editor > Data > Import Text Entries > Merge Entries. Select all the files you generated in step 2.

5. Save your changes with CTRL+S. This will update Mod 2's files with the text from Mod 1.

6. Run the mods with Mod Engine 2 and test your changes.

Note that there will still be issues if the two mods happen to use the same text IDs for modded text.