How Can i change Lexicals in Oracle BI publischer 12c with a Parameter

Question

I am trying to get the Following Dataset to work but i do not understand how i can Change "&p_bed" with a Parameter so that it can Be changed dynamicly.

Dataset:

SELECT acco.acco_id
      ,acco.account_nr
      ,acco.adressblock
      ,acco.adresszeile
      ,acco.pers_id
      ,acco.mand_id
   from crm.aktivitaeten aktv
  ,crm.aktivitaetsstatus akst
    ,crm.v_adressen2 acco
  where aktv.akst_id = akst.akst_id
    and aktv.acco_id = acco.acco_id
    and &p_bed
    and acco.pety_id = 3
  order by akst.bezeichnung desc,to_char(aktv.wiedervorlage,'YYYYMMDD') 
        ,replace(to_char(aktv.wiedervorlage,'HH24:MI:SS'),'00:00:00','23:59:59')
        ,aktv.erstellt_am desc 

For example "&p_bed" is suposed to be able to be "aktv_id = 600" but also "aktv_id >= 600 and aktv_id <= 700"

I have tried to use Oracle Help Center but either i dont understand it corectly or it is not helping my current problem.

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