Hi @StuartSmith ,
Do you want to filter your list by 8 controls?
Firstly, I suggest you use gallery to display your list , not data table.
Date table can not display directly complex data type ,for example: look up column.
Secondly, could you tell me the data type of Visiting Site column? Dropdown is not a kind of data type.
I assume that it is a lookup column too.
I've made a test for your reference:
1)insert 2 data pickers, 4 textinputs, 2 drop downs
2)set data picker1's OnChange:
Set(vardate1,true)
set data picker2's OnChange:
Set(vardate2,true)
set drop down1's OnChange:
Set(vardrop1,true)
set drop down2's OnChange:
Set(vardrop2,true)
//datapicker and drop down will have value by default, by setting its OnChange property to justify whether you make selction
3)I suggest you add a button named "search" to collect the data in the controls , since your control number is a little more.
Set the button's OnSelect:
ClearCollect(data,{name:datepicker1,status:vardate1},
{name:datepicker2,status:vardate2},
{name:dropdown1,status:vardrop1},
{name:dropdown2,status:vardrop1},
{name:textinput1,status:!IsBlank(textinput1.Text)},
{name:textinput2,status:!IsBlank(textinput2.Text)},
{name:textinput3,status:!IsBlank(textinput3.Text)},
{name:textinput4,status:!IsBlank(textinput4.Text)});
ClearCollect(datastatus,Filter(data,status=true))
4)Set the gallery's Items:
Filter(listname,If(!IsEmpty(Filter(datastatus,"datepicker1" in name)),Date>= datepicker1.SelectedDate,true),
If(!IsEmpty(Filter(datastatus,"datepicker2" in name)),Date<= datepicker2.SelectedDate,true)
If(!IsEmpty(Filter(datastatus,"dropdown1" in name)),Host .Id=drop down1.Selected.Id,true)
If(!IsEmpty(Filter(datastatus,"dropdown2" in name)),Visiting Site.Id=drop down2.Selected.Id,true)
If(!IsEmpty(Filter(datastatus,"textinput1" in name)),Textinput1.Text in First Name ,true)
If(!IsEmpty(Filter(datastatus,"textinput2" in name)),Textinput2.Text in Second Name ,true)
If(!IsEmpty(Filter(datastatus,"textinput3" in name)),Textinput3.Text in Company ,true)
If(!IsEmpty(Filter(datastatus,"textinput4" in name)),Textinput4.Text in Car Reg ,true)
)
4)About your drop downs, I suggest you set the drop down1's Items:
Choices(listname.Host)
set the drop down2's Items:
Choices(listname.Visiting Site)
You could change its Value to ID, then it will display unique ID value.
Then, after you fill in words in the conrols , click the search button , the gallery will display the filtered items.

Best regards,