Does this help?

\startxmlsetups xml:demo:base
  \xmlsetsetup{#1}{tag}{xml:demo:tag}
  \xmlsetsetup{#1}{o:tag}{xml:demo:otag} %% <---
\stopxmlsetups
\xmlregisterdocumentsetup{demo}{xml:demo:base}
\startxmlsetups xml:demo:tag
  \xmlflush{#1}
\stopxmlsetups
\startxmlsetups xml:demo:otag   %% <---
  {\bf \xmlflush{#1}}
\stopxmlsetups
\starttext
\startbuffer[test]
<?xml version="1.0"?>
<root xmlns="NameSpaceA"
      xmlns:o="NameSpaceO">
  <tag>text</tag> <o:tag>text</o:tag>
</root>
\stopbuffer
\xmlprocessbuffer{demo}{test}{}
\stoptext

> On 23 May 2022, at 09:07, Duncan Hothersall via ntg-context <ntg-context@ntg.nl> wrote:
>
> I found this unanswered question on the list from November 2020 and find today that I have the same question. How can one handle elements with the same name but in different namespaces? How should the different \startxmlsetups commands be written?
>
> Thanks.
>
> Duncan
>
> On Mon, 16 Nov 2020 at 13:37, Christoph Reller <christoph.reller@gmail.com> wrote:
> Dear List,
>
> Consider the following MWE:
>
> \startxmlsetups xml:demo:base
>   \xmlsetsetup{#1}{tag}{xml:demo:tag}
> \stopxmlsetups
> \xmlregisterdocumentsetup{demo}{xml:demo:base}
> \startxmlsetups xml:demo:tag
>   %\doif{\xmlnamespace{#1}}{o}{NameSpaceO:}
>   \xmlflush{#1}
> \stopxmlsetups
> \starttext
> \startbuffer[test]
> <?xml version="1.0"?>
> <root xmlns="NameSpaceA"
>       xmlns:o="NameSpaceO">
>   <tag>text</tag> <o:tag>text</o:tag>
> </root>
> \stopbuffer
> \xmlprocessbuffer{demo}{test}{}
> \stoptext
>
> My questions:
> - Is there a good way to have a separate XML setup for each XML namespace?
> - Alternatively, one has to do the distinction within the same XML setup. In this case, how do we get the complete namespace? (In this example: "NameSpaceA" and "NameSpaceO")
>
> Thanks in advance for your help!
>
> Cheers, Christoph
> ___________________________________________________________________________________
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>
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>
>
> ___________________________________________________________________________________
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>
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—
Bruce Horrocks
Hampshire, UK