Hi Johanna,
It is so great to see you engaging so actively with the Data Hub and you seem to be finding lots of great data! I wanted to give you a quick tip so that you can save some time now with the adding of data, but also later on with the processing.
You added the same dataset on "Gross and value, output of enterprises by industry, province and size class, personel as variables Years 2014-2019" in two different places, namely this one https://library.metabolismofcities.org/items/821826/ and that one https://library.metabolismofcities.org/items/821953/. I understand that you want it to show up in two places/layers, but you can simply do that by using the two layer tags. This has the same effect. So, while you add a document for the layer "1.4. Economic activity - figures (employees and GDP per NACE codes)", in the tagging field, you can simply also add the other layer as tag, which it also applies for. In your case, adding "1.4.5. City GDP or GVA per NACE codes (at least level 2)". See screenshot what it would look like.
In the case of that dataset, if the data is indeed specific to the city, then you don't also have to add it to 1.4 anyway. That layer is more of a "catch-all", if it doesn't fit into a sublayer.
You can still change it now by simply editing one of the documents and then you can delete the other one. (Note: I just tried this and noticed that it doesn't work at the moment for some reason. I have asked that this is fixed, see here.) It will help later when you process the document, which of course you will only want to do once.