HubSpot default themes are only available in new HubSpot accounts. If you would like to have a standard HubSpot theme installed in your existing account, follow these instructions to ensure that your account is compatible with these themes.
The standard header global group is used on all site page templates, systems page templates, thank you page pages template, and the blog template. The Header - No Navigation global group is used on all landing page templates. The naviagtion menus will default to your "Default" menu tree. To learn about changing your navigation menu tree, check out this article.
The theme global groups is located in layout can be found in your Design Manager in the Theme Name Blog folder (Templates / Custom / Page / Theme Name).
Themes use both a regular and a simple footer group across various templates. The simple footer does not have a navigation, whereas the regular footer includes a menu and other features, such as a subscription form.
All footers include a HTML module that contains the themes required scripts.
Other global groups
Certain themes have additional global modules specific to that themes, such as Breadcrumb menus.