When switching from the official GoldenDict or earlier versions of ++OCR to the latest version of GoldenDict++, you have to regroup all your dictionaries due to compatibility issues with the configuration files, which is tedious and time-consuming. However, if you have normally grouped your dictionaries by dir (under content) when you add them, regrouping them will be a no-brainer.
As the directory structure shown below (only some of the directories are listed for demonstration purposes), the subdirectories that exist under the general dictionary path (content) are the dictionary Group directories, and under each of these directories you can store as many dictionary files as you like, then the automatic grouping by directory function will use the name of the directory under content (Pronunciation, wikipedia, 文学, etc.) as the Group name and will group all the dictionaries under that name (including the subdirectories nested under it) into it:
content ├─Pronunciation │ ├─LPD3 │ ├─MW2020 │ ├─NHK日本語発音辞典 │ └─法语语音库 ├─wikipedia ├─文学 │ ├─中国神话大词典 │ ├─夜航船 │ └─DK ├─日语 │ ├─现代日汉双解词典 │ └─新英和中辞典 ├─汉英 │ ├─现代汉英词典 │ └─牛朗文韦柯反查 ├─汉语言 │ ├─中华语文知识库 │ ├─成语 │ │ ├─中华成语大词典 │ │ └─成语反查辞典 │ ├─汉典 │ └─综合写作词典 ├─科学 │ ├─Flash Animations for Physics │ └─phet ├─英汉 │ ├─ecdict │ └─英汉大词典 ├─英汉Esl │ ├─oalecd8e │ └─韦氏高阶 └─英语 ├─En-En-MW-Collegiate.Thesaurus.2015 └─Thesaurus.com 2020
The grouping will be instantly completed after clicking on the button shown with the mouse pointer above and confirming in the messagebox:
Then you can fine-tune the order of the dictionaries in each group.