[slivka_83]

C помощью EntityRule. В примере ниже управление видимостью относительно конкретного объекта задается для вкладки (Вам мунжно по аналогии сделать для кнопки).

<RibbonDiffXml>
  <CustomActions>
    <CustomAction Id="Sample.Form.account.CustomTab.CustomAction" Location="Mscrm.Tabs._children" Sequence="40">
      <CommandUIDefinition>
        <Tab Id="account.Form.CustomTab1" Command="Sample.Form.account.CustomTab" Title="Супер вкладка" Sequence="40">
          <Scaling Id="Sample.Form.account.CustomTab.Scaling">
            <MaxSize Id="Sample.Form.account.CustomTab.FirstGroup.MaxSize" GroupId="Sample.Form.account.CustomTab.FirstGroup" Sequence="10" Size="LargeMedium" />
          </Scaling>
          <Groups Id="Sample.Form.account.CustomTab.Groups">
            <Group Id="Sample.Form.account.CustomTab.FirstGroup" Command="Sample.Form.account.FirstGroup" Sequence="10" Title="Первая группа" Template="Mscrm.Templates.3.3">
              <Controls Id="Sample.Form.account.CustomTab.FirstGroup.Controls">
                <Button Id="Sample.Form.account.CustomTab.FirstGroup.FirstButton" ToolTipTitle="Кнопка 1 заголовок" ToolTipDescription="Кнопка 1 описание" Command="Form.account.CustomButton" Sequence="10" LabelText="Кнопка 1" Alt="Кнопка 1" Image16by16="$webresource:new_cub16.png" Image32by32="$webresource:new_cub32.png" TemplateAlias="o1" />
              </Controls>
            </Group>
          </Groups>
        </Tab>
      </CommandUIDefinition>
    </CustomAction>
  </CustomActions>
  <Templates>
    <RibbonTemplates Id="Mscrm.Templates"></RibbonTemplates>
  </Templates>
  <CommandDefinitions>
    <CommandDefinition Id="Sample.Form.account.CustomTab">
      <EnableRules>
        <EnableRule Id="Mscrm.Enabled" />
      </EnableRules>
      <DisplayRules>
        <DisplayRule Id="Mscrm.CanWriteaccount" />
      </DisplayRules>
      <Actions />
    </CommandDefinition>
    <CommandDefinition Id="Sample.Form.account.FirstGroup">
      <EnableRules>
        <EnableRule Id="Mscrm.Enabled" />
      </EnableRules>
      <DisplayRules>
        <DisplayRule Id="Mscrm.CanWriteaccount" />
      </DisplayRules>
      <Actions />
    </CommandDefinition>
    <CommandDefinition Id="Form.account.CustomButton">
      <EnableRules>
        <EnableRule Id="Mscrm.Enabled " />
      </EnableRules>
      <DisplayRules>
        <DisplayRule Id="Mscrm.CanWriteaccount" />
      </DisplayRules>
      <Actions>
        <JavaScriptFunction Library="$webresource:new_alert.js" FunctionName="show" />
      </Actions>
    </CommandDefinition>
  </CommandDefinitions>
  <RuleDefinitions>
    <TabDisplayRules>
      <TabDisplayRule TabCommand="Sample.Form.account.CustomTab">
        <EntityRule EntityName="account" Context="Form" AppliesTo="PrimaryEntity" />
      </TabDisplayRule>
    </TabDisplayRules>
    <DisplayRules />
    <EnableRules />
  </RuleDefinitions>
  <LocLabels/>
</RibbonDiffXml>