I have tried the below code for Magento 2 cms page custom breadcrumbs, but I got this error :
Please correct the XML data and try again. Element 'action': This element is not expected. Line: 3
Admin login -> Content-> Pages -> Add New Page -> Design -> Layout Update XML
<referenceContainer name="breadcrumbs">
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">Home</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">Home</item>
<item name="label" xsi:type="string">Home</item>
<item name="link" xsi:type="string">/</item>
</argument>
</action>
<action method="addCrumb">
<argument name="crumbName" xsi:type="string"></argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">XXXXXX</item>
<item name="label" xsi:type="string">XXXXXX</item>
<item name="link" xsi:type="string">/xxxxxx</item>
</argument>
</action>
<action method="addCrumb">
<argument name="crumbName" xsi:type="string">YYYYYY</argument>
<argument name="crumbInfo" xsi:type="array">
<item name="title" xsi:type="string">YYYYYY</item>
<item name="label" xsi:type="string">YYYYYY</item>
</argument>
</action>
</referenceContainer>