As far as I know the only direct option at the moment to see the “everything else” energy consumption is the “Untracked consumption” in the Sankey chart. This value is shown when hovered over the graph. I think that by default the graph is updated once per hour.
Of course you can create your own template sensors to calculate this value, but it would be very nice when the already existing value can be accessed directly as an entity.
Another option seems to be to access this data via SQL (see for instance this post), but I don´t have any experience with that.