SystemWeaver reports can be parameterized as described in Parameterized Reports. However, setting a parameter in a Document is not possible using <Parameters>. A Document differs from a Report in that its definition is stored in the XML attribute of the Definition Item at the end of the IREX part. The aim is to keep a document stable over time, i.e., once a document has been released, you can produce the exact same document several years later. The solution instead, is to include the parameter for what you want to select as a section item in the document. 

In the below report example, "Component A" is selected and the parameter being reported on is "Parameter Example Architecture" version (2): 

To do this in a Document, you would include "Parameter Example Architecture" (2) as a section item in the document and define what you need in the document's XML definition. The below is one example of how you can use a SystemWeaver Variable to hold a value you wish to use, equivalent to a report parameter. Note that you can also use a Context to hold that value instead of a Variable. 

    <TitlePageText x="150" y="6500">A text</TitlePageText>
    <Margins left="15" top="10" right="13" bottom="10"/>
    <ParaStyle name="hepp" alignment="right" spaceBefore="200" spaceAfter="200"></ParaStyle>
    <FontStyle name="hepp1" style="bold" font="Courier" size="24" color="Green" />

    <Variable name="current" as="Items" select="."/>

  <Variable name="ParameterExampleArchitecture" as="Items" select="/IRRS/SEIT[SID = '4PDT']"/>

   <!--Do something with the Variable value-->
    <Text>....#{? $ParameterExampleArchitecture}</Text> 
    <ForEach select="/IRRS">
  <Section title="#{Name}"> 
  <ForEach select="/XREQ"> 
        <!--Do something with the section item...-->