Linked from: https://support.boldcommerce.com/hc/en-us/articles/115005485963

bold-currency-picker-mount.liquid

{% comment %}
BOLD Multi-Currency Picker

This is the "mount point" for Bold Multi-Currency pickers.
Include this wherever you want them to appear within your theme (can appear in multiple locations)

Optional "parameters" you can pass to the include:

openDirection: 'up|down' (defaults to "up")
- Use this to tell the picker to open "upwards" or "downwards" depending on its location in your template.
- For instance, you would probably want the widget to open "down" if placed into your header
- This behaviour is controlled in CSS with the "data-open" attribute, passing either "up" or "down" (eg. data-open="down")

additionalClasses: (a space-separated list of class names)
- Use this to specify additional classes on the mount point, which you can then use to safely customize the
  Multi-Currency picker, without having to worry about a Robo-install overwriting your changes, for instance.

See https://help.shopify.com/themes/liquid/tags/theme-tags#include for more information about the include tag,
in the "Including multiple variables in a snippet" section.

These variables appear to be "scoped" to their include (not documented by Shopify), so if you set an additionalClass at
the start of a file, and include another mountpoint without an additionalClass, it will NOT use the first one.

Example:
In Liquid, you can include the snippet and pass along the openDirection and/or additionalClasses variables like this:
{%- include 'bold-currency-picker-mount', openDirection: 'down', additionalClasses: 'header' -%}

These variables are optional, so feel free to leave them out if you don't need to customize the class and/or you want
the picker to open "up"

{% endcomment %}
{% assign openDirection = 'up' %}
{% assign additionalClasses = '' %}
<span style="display:none;" class="BOLD-mc-picker-mnt {{ additionalClasses }}" data-open="{{openDirection}}" data-bold-mc-picker-mnt></span>