The beauty of this feature is that you can upload revision of an already uploaded file (the older version of the file will also be available for the group members to see!) In a Facebook group, on top of the place where you write your post, you’ll find a link Upload File. Click that and you see the following box where you can select the file you want to upload from your computer. Alternatively, you can go to the Files tab and upload the file from there: All the uploaded files (and docs created) are clubbed under the Files tab. Click on the tab to see the list of files available in the group. Now you can click on any file to view it. You can download the file or Preview it. Go to Files tab > click on the file whose revised version you want to upload > You’ll see the Upload New Revision button > Click on the button to upload a new version of the file.
You can uploaded all types of files except program files (.exe) and music files (e.g. mp3) There is no limit on the number of uploaded files. Each file, however, should be less than 25MB in size Admin of the Facebook group can control who can download the files Group members can flag an uploaded file as spam Preview is available for images and text files. These previews are opened in Facebook popup. MS-Word files are opened for preview in MS Office online.
I hope this answered your question about how to upload a file in Facebook group and also how to upload revision of an existing file. Please feel free to ask me if you have any doubts. Thank you for using TechWelkin!