It is possible to split up, but things will get much more complicated. The issue is there is no clean way to specify "None" for one location/region without adding some specialized filtering. What you would have to do is something like this.
<input searchWhenChanged="false" token="host_filter_ny" type="multiselect">
<label>NY Hosts</label>
<choice value="!!!none!!!">None</choice>
<choice value="aa">aa</choice>
<choice value="bb">bb</choice>
<delimiter>;</delimiter>
</input>
<input searchWhenChanged="false" token="host_filter_uk" type="multiselect">
<label>UK Hosts</label>
<choice value="!!!none!!!">None</choice>
<choice value="cc">cc</choice>
<choice value="dd">dd</choice>
<choice value="ee">ee</choice>
<delimiter>;</delimiter>
</input>
<input searchWhenChanged="false" token="host_filter_hk" type="multiselect">
<label>HK Hosts</label>
<choice value="!!!none!!!">None</choice>
<choice value="ff">ff</choice>
<choice value="gg">gg</choice>
<delimiter>;</delimiter>
</input>
And then specialized logic to filter out any inputs if it includes the None option
index=index
[
| gentimes start=-1
| eval hostny = "$host_filter_ny$"
| eval hostuk = "$host_filter_uky$""
| eval hosthk = "$host_filter_hk$"
| table host*
| eval hostny = if(match(hostny,"!none!"), null(), hostny)
| eval hostuk = if(match(hostuk,"!none!"), null(), hostuk)
| eval hosthk = if(match(hosthk,"!none!"), null(), hosthk)
| stats values(*) as *
| transpose
| rename "row 1" as host
| makemv host delim=";"
| stats values(host) as Host
]
| timechart min(Value) by Host limit=0
... View more