If you’re trying to select a single title but see a large parcel with multiple sites, it’s because the land is owned by a company with mineral rights, filtering by max site size or contacting the owner can help refine your options
If you are trying to select a single title and you notice a large parcel containing multiple sites like this, here is what this means:
These sites are owned by a company that holds mining or mineral rights beneath the surface. You can select some of these sites because certain portions of the land may have been sold to other companies. If you purchase a title register for one of the available sites, it will show the site's relationship to the mineral rights.
If you're interested in a site that you cannot select, you would need to contact the owner of the mineral rights for further details.
To focus on smaller sites, you can use the max site size filter and set it to low acres than the large parcel.
For an example if the large parcel is 930 acres, setting a lower value will remove it from the map view. 
This will then allow you to select the titles beneath.
In some cases all sites may be under a single title number, meaning the owner might not be willing to sell individual sites separately. In this case, you would need to contact them to inquire whether they are open to selling smaller portions or if they intend to sell the entire parcel together.