As mentioned here https://github.com/mozilla-mobile/firefox-ios/issues/16769 :
On my PC I'm used to open all bookmarks in folder with one click. A have several bookmark folders for items I want to check regularly (shopping lists, menus of nearby restaurants, web addresses of network devices at my home etc.)
I would like to have this option on iPad.
This feature is available in desktop version of Firefox and in Android version too.
Please add it to iOS/iPadOS version.